Pocket flask



FIG. 1 is a front elevation view of a pocket flask showing my new design, the opposite side being a mirror image of the shown;

FIG. 2 is a right side elevation view thereof, the opposite side being a mirror image of the shown;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof.

The broken lines in FIG. 1 of the drawings depict environmental subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for a pocket flask, as shown and described. 